Over the last few years, Internet has developed into the fastest growing means of communication and is predicted to be the main system for distributing information in the future. The Internet has become increasingly popular and the number of users is growing at a magnificent rate.
However, the popularity of the Internet, and especially the use of the Internet application World Wide Web, is putting the net under enormous capacity pressure. Traffic on the Internet doubles about every three months, with no signs of slowing down. This kind of exponential growth will eventually slow down, but several factors indicate that it is still far from any slowdown in growth.
Today, only a small fraction, about 3 to 5 percent, of all PCs have access to the Internet. It is believed that most of those who have made and will make the investment in a PC will eventually want access to the Internet. Furthermore, communication speeds between the user and the Internet infrastructure is increasing rapidly. The transition from 14.4 kbit/s modems to 28.8 kbit/s is just being completed as manufactures announce new modems at 56 kbit/s. Other technologies such as ISDN (128 kbit/s), Cable TV modems (500-10,000 kbit/s) and xDSL (2,000 to 25,000 kbit/s) are emerging. Moreover, manufacturers of household electronics are launching low costs devices to give Internet World Wide Web access through television sets, telephones, etc.
These and other factors are all contributing in making it increasingly difficult to access information on the Internet, since the system is basically being overloaded. This problem is a fact both in USA and Europe, but it is even more serious when passing information between USA and Europe. The transatlantic transmission capacity is too small to cope with the exploding Internet use.
Basically, there exists two conventional solutions to this problem. A first solution is to add more bandwidth and switching capacity, which is being done, but which carries huge costs and also faces significant technical problems. A second solution is to use so called “caching” or “mirroring” techniques. The meaning of these definitions is somewhat undefined and is also in some cases somewhat overlapping. However, “caching” basically means to keep track of the Internet traffic and to keep copies of the most frequently accessed World Wide Web files at a location closer to the user. Similarly, “mirroring” basically means to keep copies of specific World Wide Web files in a mirror server, independent of the access frequencies.
These second solutions hence involve the providing of a local copy of a World Wide Web Site of interest. For example, a copy of CNN's USA-based homepage may be provided in a cache or a mirror at a European “proxy” location, whereby European Internet users may access the CNN homepage without having to use the transatlantic communication link, thereby both attaining quicker access and at the same time lowering the load on the transatlantic link.
However, caching and mirroring also raises several technical problems. For example, current research show that to be most efficient, the cache must be near the original information source. Caching is always more efficient closer to the information content provider server then closer to the user. The problem is that, depending on the popularity of each site, the actual location of the most popular original information providers keep moving around. A cache would therefore need to be very big to be efficient.
Another problem is that the user must specify a location for the copies of the original content information, it being a cache or a mirror. Such a location is called a “proxy” and can be specified in all commonly used softwares for web access. This user interaction is difficult to obtain, given the increasing diversity of web users.
Furthermore, if the proxy is very large, as is needed to provide for a large amount of content with ever changing popularity, it will also, for economical reasons, need to cater for very many users. The proxy itself will then become a bottleneck, and access times may thus increase. Consequently, there exists a problem with the limited scaleability of the proxy technique.